Extreme frequency range?

smglbrth · May 2003

Hello All!

I have a quick question which I feel would be well answered.

On some of my CD's, just a few, and at exactly the same parts of the songs my tweeters tend to "scratch" or "cackle", if you will. I'm 99% sure there is nothing wrong with them but is there such a thing as the speakers not being able to handle all it's being given in the frequency range? I was thinking this or the recording equipment the recorders used was not adequate enough, not up to par with what they were recording since the rest of the disc sounds great!

Any thoughts?

RuSsMaN · May 2003

Nice rig.

Do you have a different source to test those few cd's on?

Cheers,
Russ

smglbrth · May 2003

Russ - Thanks for the compliment. Someday I'll have to get pictures on the site, even though there wouldn't be too many of them!

The only other thing I have in the house is a little "boombox" made by Sony. Not a very fair comparison in the least. I can't even listen to that thing anymore, makes my ears hurt....

The wife said one system, if you know what I mean, so I couldn't very well argue the point. It doesn't do me any good anyway.:rolleyes:

VR3 · May 2003

You know how to solve that? A seperate amp...lol...with a receiver the tweeters are compressed down to 20khz. With a seperate amp they reach the full 25khz+. Not sure what your running, but my tweets sound worlds better now since I purchased my adcom. Well sheat, forget that, i guess it is the speaker itself, your running B&K. lol! Nvm, hope u figure it out.

Tour2ma · May 2003

I haven't encountered a tweeter that can't reproduce the full audible range since my "Sears Silvertone".

Been years since I experienced the tweeter sound being discussed. Last I remember when I did, it turned out to be an interconnect issue, i.e., dirty connection, that showed itself in the relatively delicate upper frequencies.

smglbrth,
Suggest you make and break your RCA's using a twisting motion and see if it helps.

smglbrth · May 2003

ATC - What are the other speakers that you've heard this on? Was just thinking that maybe it was the older Polks that might do this. What you have described to me is exactly what I'm hearing on exactly the same things in the music. High voices, demanding piano keys, etc...

I also was thinking of going with Signalcable for inters, I might be able to swing that one. Do I think it'll make a difference with this, not really but who knows?

The "scratch", especially with the vocals, is similar to what you'd hear if someone was too close to the microphone singing, same with the piano keys. Seems like someone dropped the ball with the levels in the recording.

F1nut · May 2003

Originally posted by Vr3MxStyler2k3
with a receiver the tweeters are compressed down to 20khz.

Really? From what source did you receive that info???

smglbrth,

It sounds like the tweeters are clipping, just barely. If you turn down the volume a notch, does it still do it? By all means, upgrade your interconnects, but that will not affect the clipping issue.

GuitarheadCA · May 2003

*Onkyo 898 - 10 hz - 100khz (+1, -3db)

*H/K 525 - 10 hz - 100khz (+0, -3db)

*Denon 5803 - "Exteded Response to 100khz"

I think most Mid-Fi recievers can do fine around 20khz.

smglbrth · May 2003

F1Nut - Turning the volume down doesn't seem to help. The drivers are barely moving and the tweeters still do it.

Maybe it's the crossovers? In my 8t's there is one original and one replacement. I didn't replace the one, it was like this when I bought them. All the other stuff, drivers and tweeters, has already been replaced. I'm a stickler for having everything look exactly the same.

So.........

F1nut · May 2003

smglbrth,

Hmmmm.....I'm out of ideas. Talk to Ken at Polk and see what he says.

Tour2ma · May 2003

smglbrth,
Did you try cleaning up the IC jacks?

smglbrth · May 2003

Tour - I don't make my own jacks but could you give me some advice on exactly how to clean them up? They are gold plated so I wouldn't know what to use as to not mar or take off the finish.

Suppose you could be talking of making new ends....... If this is the case, disregard my first response.

Tour2ma · May 2003

Just make and break the RCA connections with a twisting motion a few times. This will clean the contact surfaces. Nothing will be marred that you will be able to see with the connections made.

Give it a shot... nothing to lose...

Jockos · May 2003

I sorta have the same problem with my 5Bs.On piano and vocals it seems gritty and coarse, even when the volume is low. I switched to an older 2 channel yamaha which I have connected to my 11t's and it sounded smooth.
I believe the problem is with my reciever which is a newer Yamaha. It seems as though the gain on the preamp or amp might be to high. I'm going to send it in to the shop and see what they say, although these kinds of problems are hard to explain to a service tech.
If you have different set of speakers try using them. By the way I just got my Lsi 15's and will be trying them on the same receiver. My 11t's are running with a older 2 channel yamaha. It sounds very smooth. Let me know if you can switch to another pair of speakers.

Jockos · May 2003

Just got my LSi 15's 2 days ago and the sound out of my reciever is very smooth, I believe the tweeters on my 5Bs could be responsible. Maybe the aging SL2000 tweeters can't handle the dynamic notes anymore. Look's like I'm back to the beginning of this mystery.

smglbrth · May 2003

Tour - Did the twisting thing, to no avail. But it was worth the try!

Jockos - I don't have a different pair of speakers. I replaced my SL2000's with the SL2500's (?), at least, I think that's what they are. They look just like the 2000's but are black instead. This is the replacement Polk sent me anyway.

Make me wonder about the age of speakers. Not the actual physical age but the age in which the crossovers and the like were made. I'm pretty sure, with the dynamics of recorded material today, that if I hooked up speakers made from the early 70's to the B&K equipment I have I seriously doubt it would sound all that good. Like putting a HUGE whitewall tire made for 80's cars on a brand new Vette, it just wouldn't work. Realizing this probably isn't a fair comparison, before I get nailed for it, this is just a word picture for what I'm describing.

But....., I'm probably wrong, it's happened before and it'll happen again!:D

(BTW - Sorry I didn't answer both of you back right away, this house has been a real zoo lately)

F1nut · May 2003

smglbrth,

So, if I understand you, Polk sent you replacement tweeters and they still do the same thing? What about the crossovers??? Ask a friend if you can borrow an amp just to rule that out. I disagree with your statement about older speakers not being able to "keep up", a good speaker is a good speaker no matter how old.

smglbrth · May 2003

F1nut - One of the older 2000's got pushed in by accident. So instead of ordering one I ordered two so they would match. Both the 2000's and 2500's made the "crackle". Before I had the B&K setup I had Audiosource, those amps made the "crackle" as well. Suppose I shouldn't say "made the crackle" but the "crackle" happened with both amps.

About the speakers being able to "keep up", knew I'd get nailed for that!!

F1nut · May 2003

So what about the crossovers? I assume that your speakers didn't always make this noise, did they?

BTW, that wasn't a nail, just a slight tap.

smglbrth · May 2003

F1nut - When I bought the speakers originally, used, I did notice one crossover was original and that one was a replacement. I started out with a receiver, then went to separates. With the receiver I did not notice the "crackle". After the separates came I did. The two Audiosource amps I had were bridged, one for each channel and I only noticed the crackle on the right channel, mainly (I had always wondered if one amp was pushing more than the other since they both had gain adjustments on them). After I purchased the B&K, after I sold the Audiosource amps, I noticed the "crackle" distinctly on both sides more often. This leads me to believe that the recordings are a little too much up on the levels. Since I was constantly getting into better equipment the crackle was becoming more noticeable.

I had thought of buying new crossovers but heard that Polk quit making them for the 8t. Since I don't know how to test them or mess with electronics in general I've left them in. I'm pretty good with a wrench but with electronics I'm probably better served with a sledgehammer!!

Sure wish I had another thousand laying around. I would buy the new Lsi 9's and give them a run for their money.....keeping the 8t's of course.

No offense taken from before, different points of view are fun if people are willing to learn from them!

mantis · June 2003

Puzzling...
I'm gonna say you have bad tweeters.If they crackle,there bad.Nothing worse then a blown tweeter.

If your going to replace interconect and want to tame down some of the brightness,then your going to have to look into the network interconnects like Transparent or MIT.The networks don't allow for signals above 20khz to pass.They feel this reduces unwanted noise,which is where most of it is in the uppper freq's.

I'm also thinking you should call polk about your problem.See what they say.It's so hard to correct a problem without hearing it.I can only make a educated guess.

F1nut · June 2003

Dan,

Did you read the entire thread? He has new tweeters and it's still doing the same thing.
As far as MIT cables go, read this. "The ISN Technology by MIT exhibits articulation ranging from 50% -57% across the frequency range of 10Hz - 35kHz, far beyond the ability of conventional audio cables, No Music Lost! No Compromises!" There is no cut off at 20kHz. And for the record, MIT's founder/owner Bruce Brisson worked for Monster, not Transparent.

F1nut · June 2003

smglbrth,

I have speakers with the SL2000 tweeters and have never had this problem with any recording, new or old. I still think the problem is with the crossovers. Polk still lists the crossovers as available on the parts list or I'll bet if you sent them into Polk they would test them and repair them if need be. Call Ken Swauger on Monday and see what he thinks.

burdette · June 2003

smglbrth,

I'm not sure what you're wanting to do now, I'm not even totally sure I understand completely your situation.. but I may have some offers to mess things up more.

I have two crossovers from a pair of RTA8Ts... I have two brand new replacement SL2000s (black cones)... sounds like you should have one old SL2000 that is OK and one that the cone is pushed in? (did you try pulling it out with a little tape?)

I was hoping to complete SOME sort of DIY project using various scrounged Polk parts, but I'm starting to believe that I'm not going to be able to do what I wanted (because the drivers aren't shielded). And even if I get it to work, I need only one of the crossovers.

If you have ANY interest in these crossovers, or one of them, if you're maybe interested in getting rid of one or both 'old' SL2000s... if you're maybe interested in the brand new SL2000s... send me an email and we can chat about it.

Even if I can get my project going as I want, I could most likely sell you one of the crossovers. I got them from a reputable seller here on the boards; I've had both hooked up to drivers to ensure continuity (although the drivers weren't driven hard).

smglbrth · June 2003

Burdette - You didn't make things more complicated, but I'm going to type something that still makes me wonder!

Since it's been so busy around here lately figured I'd better get the couple of CD's out that the "scratch" was heard on and pinpoint the exact locations in the songs. Figured I'd give a call to Polk to inquire about their knowledge and ideas. As I was getting close to the questionable areas I heard nothing but sweet piano and voice. What was this?? I listened very intently the next time, not to mention at a higher volume and there was no scratch, at all.... After listening another half dozen times, to the same areas where I heard it before I still heard nothing. Talk about a fluke! (Not to mention it makes me look like a fool)

The only thing I can figure is this. Since the B&K amp was bought new, and only about three months old right now, maybe it needed more of a break in that I thought. I even doubt this theory though, it even sounds crazy.

But......., maybe that's just what it was, a fluke since all I hear now is some of the most full piano and voice tones I've ever heard on a system before.

Sorry for all the hassle guys and thanks for your insight, I did learn a little!

Dang, I love this B&K stuff.........:D

Tour2ma · June 2003

smglbrth,
Fantastic... Glad to hear things have smoothed out for you.

Now you just have to worry about the facial muscle aches from sitting back and smiling ear to ear...

Extreme frequency range?

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